:root {
  --primary: #059669;
  --primary-hover: #047857;
  --bg-dark: #0f172a;
  --bg-light: #f8fafc;
  --card-bg: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --danger: #ef4444;
  --warning: #f59e0b;
  --shadow: 0 2px 6px rgba(0,0,0,0.04);
}

/* ---------- Dark Mode ---------- */
[data-theme="dark"] {
  --bg-dark: #0a0f1e;
  --bg-light: #111827;
  --card-bg: #1e293b;
  --text-main: #e2e8f0;
  --text-muted: #94a3b8;
  --border: #334155;
  --primary: #10b981;
  --primary-hover: #059669;
  --shadow: 0 2px 6px rgba(0,0,0,0.3);
}
[data-theme="dark"] header {
  background: #0f172a;
}
[data-theme="dark"] .card {
  background: var(--card-bg);
  border-color: var(--border);
}
[data-theme="dark"] input,
[data-theme="dark"] select {
  background: #1e293b;
  color: var(--text-main);
  border-color: var(--border);
}
[data-theme="dark"] .part-card {
  background: var(--card-bg);
  border-color: var(--border);
}
[data-theme="dark"] .stock {
  background: #1e3a2a;
  color: #34d399;
}
[data-theme="dark"] .out-stock {
  background: #3b1c1c;
  color: #f87171;
}
[data-theme="dark"] .cart-line-grid {
  border-color: var(--border);
}
[data-theme="dark"] .cart-line-grid .qty-controls input,
[data-theme="dark"] .cart-line-grid .qty-controls button {
  background: #1e293b;
  border-color: var(--border);
  color: var(--text-main);
}
[data-theme="dark"] .cart-line-grid .remove-btn {
  color: #f87171;
}
[data-theme="dark"] h2 {
  color: var(--text-main);
  border-color: var(--border);
}
[data-theme="dark"] .part-name {
  color: var(--text-main);
}

* {
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-light);
  color: var(--text-main);
  padding: 24px;
  transition: background-color 0.2s, color 0.2s;
}

header {
  background: var(--bg-dark);
  color: white;
  padding: 24px;
  text-align: center;
  border-radius: 12px;
  margin-bottom: 24px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transition: background 0.2s;
}

header h1 {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

header p {
  color: #94a3b8;
  font-size: 0.9rem;
  margin-top: 4px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 24px;
}

@media (max-width: 850px) {
  .container {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--card-bg);
  padding: 20px;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  transition: background 0.2s, border-color 0.2s, box-shadow 0.2s;
}

h2 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  border-bottom: 2px solid var(--border);
  padding-bottom: 10px;
  color: var(--bg-dark);
  transition: color 0.2s, border-color 0.2s;
}

label {
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 12px;
  display: block;
}

input, select, button {
  width: 100%;
  padding: 10px 12px;
  margin-top: 6px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

input:focus, select:focus {
  outline: 2px solid var(--primary);
  border-color: transparent;
}

button.btn-primary {
  background: var(--primary);
  color: white;
  border: none;
  font-weight: 600;
  cursor: pointer;
  margin-top: 18px;
  transition: background 0.2s ease;
}

button.btn-primary:hover {
  background: var(--primary-hover);
}

.filter-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  gap: 12px;
}

.parts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.part-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: background 0.2s, border-color 0.2s;
}

.part-card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  background: #cbd5e1;
}

.part-details {
  padding: 14px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.part-name {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 4px;
  color: var(--bg-dark);
  transition: color 0.2s;
}

.part-cat {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.price-stock {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.price {
  font-weight: 700;
  color: var(--primary);
  font-size: 1.05rem;
}

.stock {
  font-size: 0.75rem;
  background: #dcfce7;
  color: #15803d;
  padding: 3px 8px;
  border-radius: 12px;
  font-weight: 600;
  transition: background 0.2s, color 0.2s;
}

.out-stock {
  background: #fee2e2;
  color: var(--danger);
}

.actions {
  display: flex;
  gap: 6px;
}

.btn-edit {
  background: var(--warning);
  color: white;
  border: none;
  padding: 6px;
  border-radius: 4px;
  cursor: pointer;
  font-weight: 600;
}

.btn-del {
  background: var(--danger);
  color: white;
  border: none;
  padding: 6px;
  border-radius: 4px;
  cursor: pointer;
  font-weight: 600;
}

/* ---------- Cart line grid (checkout) ---------- */
.cart-line-grid {
  display: grid;
  grid-template-columns: 56px minmax(100px, 1fr) 110px 80px 28px;
  gap: 8px;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  overflow: hidden;
  transition: border-color 0.2s;
}

.cart-line-grid .item-image {
  width: 56px;
  height: 56px;
  object-fit: cover;
  border-radius: 6px;
  background: #e2e8f0;
}

.cart-line-grid .item-info {
  min-width: 0;
  overflow: hidden;
}

.cart-line-grid .item-name {
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cart-line-grid .item-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.cart-line-grid .qty-controls {
  display: flex;
  align-items: center;
  gap: 4px;
}

.cart-line-grid .qty-controls input {
  width: 44px;
  text-align: center;
  padding: 4px 2px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-weight: 600;
  font-size: 0.9rem;
  flex-shrink: 0;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.cart-line-grid .qty-controls button {
  width: 26px;
  height: 26px;
  border: 1px solid var(--border);
  background: #f1f5f9;
  border-radius: 4px;
  cursor: pointer;
  font-weight: bold;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background 0.2s, border-color 0.2s;
}

.cart-line-grid .item-total {
  font-weight: 700;
  text-align: right;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cart-line-grid .remove-btn {
  background: transparent;
  border: none;
  color: var(--danger);
  cursor: pointer;
  font-size: 1.2rem;
  padding: 0;
  text-align: center;
  flex-shrink: 0;
  transition: color 0.2s;
}

@media (max-width: 700px) {
  .cart-line-grid {
    grid-template-columns: 40px minmax(80px, 1fr) 80px 60px 24px;
    gap: 6px;
    font-size: 0.85rem;
  }
  .cart-line-grid .qty-controls input {
    width: 36px;
    font-size: 0.8rem;
  }
  .cart-line-grid .qty-controls button {
    width: 22px;
    height: 22px;
    font-size: 0.8rem;
  }
}

/* ---------- Floating Controls (Dark Toggle + Scroll-to-Top) ---------- */
.floating-controls {
  position: fixed;
  bottom: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 999;
}

.floating-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: var(--primary);
  color: white;
  font-size: 1.3rem;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.floating-btn:hover {
  transform: scale(1.05);
  background: var(--primary-hover);
}

.floating-btn.dark-toggle {
  background: #1e293b;
  color: #fbbf24;
}
.floating-btn.dark-toggle:hover {
  background: #0f172a;
}
[data-theme="dark"] .floating-btn.dark-toggle {
  background: #fbbf24;
  color: #1e293b;
}
[data-theme="dark"] .floating-btn.dark-toggle:hover {
  background: #f59e0b;
}

.scroll-top-btn {
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px);
  transition: all 0.3s ease;
}
.scroll-top-btn.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}